RE: locking down snort

["Andrew Shore" <andrew.shore () holistecs com>]

When setting up snort (or any other packet sniffer) the best method is
to use 2 nics. One nic has an IP address and is used for management only
the second is used to do the sniffing and has no address. 

This way management traffic does not get monitored and no one can
connect to the sniffing port.

Also in larger networks the sniffer management port can sit on the
management/server vlan and the analysing port can  sniff other vlans
(although be careful about crossing security domains ie short circuiting
firewalls etc)

 
Andrew Shore
Senior Security Specialist
DDI. 01302 308 165
andrew.shore () holistecs com
 
 
 
Company Number 04943010
VAT Number 828 8635 82
 
 
Holistic Technologies Ltd
Unit 7 Shaw Wood Business Park
Shaw Wood Way
Doncaster
South Yorkshire
DN2 5TB
T. 0870 240 1442
F. 0870 240 1443
www.holistecs.com
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-----Original Message-----
From: Jose Guevarra [mailto:jose () iquest ucsb edu] 
Sent: 24 June 2004 18:29
To: security-basics () securityfocus com
Subject: locking down snort

Hi,


 I have some machines running snort.  I'd like to restrict ssh/http and
other access to them. However, I'm not sure if in doing so, would snort
not
'grab' and analyze traffic hitting those ports.  I guess I'm asking 

- if I blocked those ports from the outside world would I still detect
say a
port scan on those ports?

- Who captures the packets first: Firewall(IPTABLES) or SNORT?

Thanks, 



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